package prefuseDemos;

import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class test7 extends JPanel {

public test7() {

  JButton btn1 = new JButton("Button1");
  add(btn1);

}

public static void main(String[] args) {
  JFrame frame = new JFrame();
  frame.getContentPane().add(new test7());

  //frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.addWindowListener(new FrameListener());
  
  frame.setSize(200, 200);
  frame.setVisible(true);
}
}
class FrameListener extends WindowAdapter
{
 public void windowClosing(WindowEvent e)
{
  System.exit(0);
}
}
